#################################################
#
# Read using blocking channel
#
#################################################
package require Tcl 8.6-
package require tls
set host "www.google.com"
set port 443
set path "/"
set protocol "http/1.1"
#
# Send HTTP Get Request
#
proc http_get {ch host path protocol} {
puts $ch [format "GET %s %s" $path [string toupper $protocol]]
puts $ch [format "User-Agent: Mozilla/4.0 (compatible; %s)" $::tcl_platform(os)]
puts $ch [format "Host: %s" $host]
puts $ch [format "Connection: close"]
puts $ch ""
flush $ch
}
# Save returned data to file
proc save_file {filename data} {
if {[catch {open $filename wb} ch]} {
return -code error $ch
}
fconfigure $ch -buffersize 16384 -encoding utf-8 -translation crlf
puts $ch $data
close $ch
}
proc handler {ch} {
append ::data [read $ch 4096]
if {[eof $ch]} {
close $ch
set ::wait 1
}
}
proc read_nonblocking {host port path protocol} {
set result ""
# Open socket
set ch [::tls::socket -servername $host -request 1 -require 1 -alpn [list [string tolower $protocol]] $host $port]
chan configure $ch -blocking 1 -buffering line -buffersize 16384 -encoding utf-8 -translation {auto crlf}
fileevent $ch readable [list handler $ch]
# Initiate handshake
::tls::handshake $ch
after 1000
# Send get request
after 5000 [list set ::wait 1]
http_get $ch $host $path $protocol
vwait ::wait
catch {close $ch}
}
set data ""
read_nonblocking $host $port $path $protocol
save_file "read_nonblocking_webpage.txt" $data